JPS6123435B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for installing a new pipe in an existing pipe that is aging and has a curved pipe in the middle.

When replacing an aging existing pipe with a new pipe, a ductile straight pipe is used as the new pipe, and shafts 2 and 3 are provided at both ends of the existing pipe line 1 as shown in Figure 1.
Using a jack 4 installed in one of the shafts 2 or a winch (not shown), etc., insert the socket of the subsequent ductile straight pipe 5' into the socket of the preceding ductile straight pipe 5, and then similarly. The method of installing straight pipes in the existing pipe line 1 while sequentially joining them is known as the existing pipe piping method.

By the way, there is no problem with this construction method if the existing pipeline 1 is almost straight as shown in Figure 1, but if there is a curved line between the existing pipelines 1' and 1'' as shown in Figure 2. If the pipe line 6 is formed, the new pipe will have a long length as described above, so the curved pipe line 6 will be formed.
If it is impossible to pass through the section and the method is to be implemented in spite of this, curved pipe 6
A third shaft (not shown) must be provided in the section. Therefore, if it was not possible to construct a shaft in this area due to external factors such as traffic or housing conditions, there was the inconvenience that this construction method could not be implemented.

An object of the present invention is to provide a piping construction method within an existing pipe that can be implemented even if the existing pipe has a curved pipe as described above, and can eliminate the conventional inconveniences. .

In order to achieve the above object, this invention method is used in the piping construction method as described above, when the existing pipe is a curved pipe in the middle, each pipe is made of steel from one of the shafts to the curved pipe. After inserting short pipes or curved pipes to form a new curved pipe, insert a plurality of ductile straight pipes into the sockets from both shafts toward the new curved pipe, with the steel straight pipe at the beginning. It is characterized in that the steel pipe is inserted while being fitted and joined in sequence, and the tip of the first steel pipe is brought into contact with the end of the short pipe or curved pipe and welded and joined. According to this invention method, after forming a new curved conduit in advance using short pipes or bent pipes, the tip of the steel straight pipe at the head of a plurality of ductile straight pipes is attached to the end of the short pipe or bent pipe. Since it is joined, even if there is a curved pipe in the middle of the existing pipe, there is no need to install a shaft there, and it is possible to insert a new pipe, which saves the construction cost required for installing a shaft. Since there are no environmental changes caused by the installation, various troubles can be prevented from occurring.

Furthermore, the short pipe or bent pipe that forms the new curved pipe is made of steel, and the tip of the steel straight pipe is brought into contact with the end of the short pipe or bent pipe and joined by welding. Even in the case where the pipe diameter is large, by shortening the length of short pipes or curved pipes, they can pass through curved pipes, and construction in various complicated existing pipes becomes possible. In other words, when joining a short pipe or a curved pipe and a straight pipe using the normal fitting method, a socket must be provided in the short pipe or curved pipe.
Therefore, there is a limit to how short the length can be, and it may be impossible to pass through curved pipes with a large degree of bending. However, by using the welding method described above, curved pipes can be It is no longer affected by the degree of curvature. Further, by using the welding joining method, leakage and pull-out at the joint can be reliably prevented, and unlike the fit-in joining method, there is no need to provide a watertight member or a detachment prevention mechanism.

Embodiments of the present invention will be described below with reference to FIG. 2 and subsequent drawings.

First, rust lumps in the existing pipes 1', 1'', and 6 are removed by appropriate means.

Thereafter, a bent steel pipe 7 having a bending degree corresponding to the curved pipe line 6 and having a short length is inserted from the shaft 2 or 3 toward the curved pipe line 6 and installed in the curved pipe line 6.
In this case, if the degree of curvature of the curved pipe 6 is too large to allow the curved pipe 7 to pass through, the curved pipe 7 is divided into a plurality of shorter pipes and the pipes 6 are successively
After being inserted into the pipe, the abutting portions thereof are joined by welding within the pipe line 6 to form the curved pipe 7.

Next, as shown in Fig. 3, a straight steel pipe 9 with a socket formed at the rear end is inserted into the shaft 2 using a jack 4 in the same manner as in the conventional construction method, and then a ductile straight pipe 5 is inserted into the shaft 2. Then, the following ductile pipe 5 is joined by fitting the socket into the socket of the steel pipe 9, and then the same process is repeated to join the ductile pipes one after another while inserting the pipe into the existing pipe 1'. Insert into.

Next, as shown in FIG. 4, when the tip of the steel pipe 9 comes into contact with the end of the steel pipe 7, the abutting part is joined within the pipe line 6 by welding.

Next, as shown in FIG. 5, ductile pipes 5, 5' are inserted from the shaft 3 into the existing pipe line 1'' with the steel pipe 9' at the beginning in exactly the same manner as described above, and the steel pipe 9' at the beginning is inserted. The tip is welded to the end of the steel pipe 7 (FIG. 6).

Fig. 7 shows a case where there are two curved pipes 6', 6'', and in this case, the straight pipe 1 in the middle can pass through the curved pipes 6', 6''. It is formed by welding and joining a plurality of short steel tubes 10, and this short tube 10 is formed by welding together a plurality of short steel tubes 10.
7' is installed in the straight line 1 before it is installed.

Note that the ductile pipes 5 and 5' joints by sockets and insertion ports in each of the above embodiments have a structure that has been conventionally used, so a detailed explanation is omitted, and the direction is reversed, i.e. The trailing tube may have a socket at its front end, and the leading tube may have an inlet at its rear end.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a typical conventional existing piping construction method, Figs. 2 to 6 are temporary schematic explanatory diagrams of the construction method according to the present invention, and Fig. 7 is another construction method using the construction method according to the present invention. It is a schematic explanatory drawing of an example. 1, 1', 1'', 1...Existing pipe, 2, 3...
Vertical shaft, 5,5'...Ductile straight pipe, 6,6',
6″...Curved pipe, 7, 7′...Steel curved pipe, 9,
9'...Steel straight pipe.

Claims (1)

[Claims] 1 In a piping construction method in which a vertical shaft that opens on the side of an existing pipe is provided at both ends of the pipe, and a new pipe is installed within the existing pipe using these two shafts, the pipe has a curved pipe in the middle. In this case, after forming a new curved pipeline by inserting a steel short pipe or curved pipe from either shaft toward the curved pipeline, from both shafts toward the new curved pipeline. A plurality of ductile straight pipes are inserted into the sockets with the steel straight pipe at the beginning, and are sequentially joined while the ends are brought into contact with the ends of the short pipes or curved pipes. A method of piping inside existing pipes that is characterized by welding and joining.